HOLLYWOOD - J.J. Abrams may have muscled up his version of

Star Trek

, but the franchise will always be the domain of geeks like the California Institute of Technology prodigies on CBS's

The Big Bang Theory

.

Exhibit A: the popular YouTube.com video of Sheldon, played by Jim Parsons, explaining the rules of "Rock, Paper, Scissors, Lizard, Spock."

"It's very simple: Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and, as it always has, rock crushes scissors."

That kind of giddy celebration of the nerd mind has given the program, created by Bill Prady and Chuck Lorre, a steadily growing audience, with promise for more: The show, which drew 9.76 million viewers for its second-season finale May 11, was picked up in March for two more years in a multimillion-dollar deal.

Parsons, along with the show's other lead geek, seasoned sitcomer Johnny Galecki, met in a fancy diner one afternoon in Hollywood to ponder their luck.

"It's security I never dreamed I'd be able to say I have," Parsons says.

The Houston-native actor, who was a regular on Judging Amy, is wittily verbose like his character, but he doesn't pretend to have the scientific aptitude.

When asked if he's learned any new concepts from the show - Schrodinger's cat, anyone? - he blinks and says, "Learned? More like memorized in less than a week and then promptly forgotten."

Galecki, who's still fondly remembered as Darlene's slouchy boyfriend on Roseanne, plays Leonard, the straight nerd to Sheldon's fussy one. For him, two more years means "so many more lines. It's not like we get to just sit back now."

Well, maybe some of them do. Listen to Galecki and Parsons talk about costar Kaley Cuoco, who plays Penny, the sweet but dippy waitress next door, and you might believe she has super powers.

"I don't know how she does it," Parsons says, "but she always has every single word memorized."

"She never makes a mistake," Galecki adds.

Despite the intricate monologues, the stars, in some ways, can put up their feet a bit.

Galecki, for instance, has learned to play Leonard with a little more cool than in the first season.

"I'd watch the show and see moments where I worked some gesture too much or overemphasized my walk. But I realize now that I can just relax into it. It's all muscle memory now."

But muscle memory doesn't make up for a grueling schedule of rehearsal, memorization, and rewrites.

"We're pretty serious about silly," Galecki says. "We don't really do pranks on set."

Is that mood due to pressure from the famously spirited Chuck Lorre? The reigning maestro of the sitcom, with hits including Dharma & Greg and Grace Under Fire under his belt, has been known to clash with TV critics and his leading ladies of yore, such as Brett Butler.

"I'd heard those stories about Chuck, too," Galecki says. "But it's never been the case for me. He's working too hard for any of that."

Lorre, once a guitarist for hire, has "this incredible ear," Galecki says. "He can just hear the beats and inflections of dialogue. I'll step into his office and he'll be playing the guitar between writing bits."

By all accounts, The Big Bang Theory is a harmonious set. In addition to group trips to Comic-Con and the like, the actors sometimes get together or go to see a movie.

But Galecki points out that since they got the two-year thumbs up, they're not hanging out with the same frequency.

"We've been through the honeymoon period," he says. "We'll be riding this wave together for a while."